| BackgroundWith the population aging increase and development of transportation, the patients with severe acetabular fracture caused by car accident and osteoporosis fracture is dramatically increasing。The complexity of acetabular fracture operations is still a great challenge for orthopedic surgeons. In recent years, the locking compression plate (LCP) with the preset direction of lock screws and better security has been widely applied for internal fixation of periarticular fractures. However, the LCP is still rarely used for the treatment of acetabular fractures.Objective①To measure and analysis the surface of the Chinese acetabular CT san three dimensional reconstruction models and search for the anatomical Discipline of acetabular surface.(2)To design the anatomical locking plate with shape conformed with bone surface and preset direction of lock screws avoiding the articular according to the discipline of bone surface.③To realize acetabular anatomical locking plate clinical application by costom-made method, follow up the patients treated with the costom-made plate to estimate the feacibility.Methods①Imaging data of the patient's pelvis were obtained through 64-slice spiral CT (SIMENS Corporation, Germany) scan. The DICOM file format obtained by scan was introduced into the Materiaise's interactive medical image control system (Mimics, version 10.0) software for three-dimensional (3D) reconstruction and editing, to remove impurities and the image of the femur part, results saved as the STL file format. The abovementioned STL file was introduced into the IMAGEWARE software (Imageware V12.1, US EDS Corporation), to design of plate screws. Establish Standard surface with selected anatomical feature points; Set one tenth of acetabular diameter the measurement unit of three-dimensional coordinate system to eliminate the differences of the acetabular surface; Note the measure points and measure the distance from the points to acetabular surface z (a,b); conduct statistical analysis of acetabular diameter d,and obtain statistics mean D. Conduct statistical analysis of z (a,b), and obtain statistics mean Z, which multiplied by D to obtain the standard surface (SS) storm points.②Design the anatomical locking plate with shape conformed with bone surface and preset direction of lock screws avoiding the articular in reference to the location of postacetabular reconstruction plate. The well designed plate and screws were saved as the STL file for further surgical design and plate processing.③Manufacture the costom-made anatomical locking plate and apply clinically and follow up.Results①The difference of postacetabular surface was analyzed successfully and the storm points of the postacetabular surface was obtained, which will be authorized invention patents by state netellectual property office in 12 months.②The anatomic shape of the acetabular anatomic locking plate obtained using CAD/CAM technology was completely consistent with the postacetabular surface and the preset knocking direction of screws completely avoided the acetabulum.③The costom-made acetabular locking plate obtained by CAD/CAM technology was applied clinically.The six cases of clinical application obtained satisfactory short-term efficacies.Conclusions①In the IMAGEWARE software, measurement of pelvic three dimensional model by choosing anatomical feature points, standardizing the measurement unit and mimicking storm points method can be achieved to analyze the anatomical difference of postacetabular surface and obtain the storm points of postacetabular surface.②These data show that personalized design based on CAD/CAM technology is an accurate and reliable method of obtaining the perfectly fit anatomic plate and reasonable directions of the locking screws.③The personalized plate shape design and manufacturing based on CAD/CAM technology may achieve good surface fitness with the reference substances (mirror models or fractured acetabulum following reduction) in preoperative design, computer stimulation, mimicking surgery on the model as well as clinical surgery. |
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